Method of making armature coils



Feb. 2, 1932. v 5, APPLE 1,843,590

METHOD OF MAKING ARMATURE COILS Filed Oct. 26. 1928 Ti Z 7 5 /2 157.1 I

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Patented Feb. 2, 1932 r Par METHOD OF IvIAKING ARMATURE COILS Application filed. October 26, 1928. Serial No. 315,339.

This invention is shown, tho not claimed, in my copending application, Serial Number 234,158 and relates to bar wound armature coils suitable for radial entry into open core 6 slots, the open ends of the loops being somewhat prolonged and specially formed so that commutator segments may be composed of pairs thereof.

An object of the invention is to reduce the cost of an armature by eliminating the separately made commutator, thereby reducing the number of parts and the amount of labor and material required.

Another object is to improve the electric circuit thru an armature by eliminating the soldered, brazed or welded joints commonly made to connect the bars of the winding to the commutator segments.

Further objects will be apparent from a consideration of the following description,

reference being had to the drawings where- Fig. 1 is a cross section thru wire from which the winding units maybe made.

Fig. 2 shows a length of wire Fig. 1 bent back upon itself to hairpinform.

Fig. 8 is a plan view of a complete loop made from Wire Fig. 1. i Fig. 4 is an end View of Fig. 3.

Fig. 5 shows two loops placed in a core. Fig. 6 shows a completed armature, partly in section, wound with wire loops Figs. 3

and 4.

Fig. 7 is a transverse section thru a mold 35 used to bind the loops together.

Similar numerals refer to similar parts thruout the several views.

Heretofore bar wound armatures of the open slot type have usually been made by providing loops of bar stock or wire and radially entering these loops into the open core slots, then providing a separate commutator and joining the open ends of the loops to bars of the commutator by soldering. The volume of current carried by these bar windings is usually large and frequently the solder is melted and the usefulness of the armature destroyed. This, together with the fact the cost of separately producing a conventional commutator is considerable, and

the labor incident to, joining the loop ends to the commutator bars is costly, makes the hereinafter described method of great value both as to cost and dependability.

Tire of a cross section 11 Fig. 1 is preferably made by passing a round wire of standard gauge between rollers, but it may be drawn directly to the shape shown. This wire is cut to suitable lengths and each length is bent double to hairpin form as shown in Fig. 2, providing a conductor bar 12, which later becomes a part of the outer layer of the winding, and a conductor bar 13, which later becomes part of the inner layer of the winding, left oined together at 14. The hairpins are next spread to loop form, and Fig. 3 shows such a loop when bent for a wavewinding, tho it is obvious that a loop for a lap winding is as readily produced from a like hairpin. The loop 25, Figs. 3 and 4:

comprises an outer layer conductor bar 15,

an inner layer conductor bar 16 joined at 1% by back lead portions 17 and 18, and front lead portions 19 and 20 terminating in commutator lugs 21 and 22.

Lugs 21 and 22 are produced by striking the free ends of the loop in a die are not necessarily of greater cross sectional area than the wire Fig. .1, tho they may be stoved slightly endwise in the die to increase their cross sectional area. The lugs however, are of somewhat greater radial depth than the bars. Grooves 23 and 2 1 are pressed lengthwise in the sides of lugs 21 and 22 respectively, to help increase the radial depth of the lugs, and to provide ledges whereon the commutator binding means may bear.

Fig.5 shows two loops 25 laid in the slots of a core 26, and themanner in which one pair of lugs 21 and 22 here come together to continue the circuit and form one commutator segment is typical of the entire'winding.

When an entire set of loops 25 have been entered into the slots of core 26, the structure is placedin mold where insulating material 27 may be molded between and around front leadportions 19 and 20 and between segments composed of pairs of lugs 21 and 22, into grooves 23 and 24 to bind the structure together.

Fig. 7 shows a cross section taken thru mold 35 immediately above the ends of the commutator segment. The mold consists, in part, of a ring 28 which is forced over jaws 29, each aw having a small spacing tang 30 extending between segments composed of pairs of lugs 21 and 22. The radially inward pressure of j a-ws 29 holds the flat sides of a pair of lugs 21 and 22 in electrical contact and holds the pairs of lugs spaced apart so that insulation may be molded to surround shaft 31 filling space 32, and to extend thru openings 33 into pockets 34 to bind the lugs together to form a commutator.

Having described my invention, I claim 1. The method of making an integral unit of an armature winding which consists of folding a length of stock back upon itself to hairpin form, spreading the legs of the hairpin to form a loop, open at one end and closed at the other, and striking the open ends of the loop in a die to provide wedge shaped lugs and of suitable depth to compose a com-i mutator segment, the two lugs together be ing required to provide sufficient thickness for the said segment.

2. The method of making an integral unit oi. an armature winding which consists of cutting a length of stock sufficient for one turn of the winding, folding it back upon itself to hairpin form, shaping it to loop form wherein one leg of the loop is positioned to adapt it to a half turn of the outer layer of the winding and the other leg is positioned to adapt it to a half turn of the inner layer of the winding and each of the two ends of the loop is shaped to provide wedge shaped lugs and positioned to compose the axial length and the radial width required for a commutator segment, the two lugs taken together being of suitable circumferential thickness for the aforesaid purpose.

3. The method of making a turn of an armature winding and two half segments of the commutator integral, which consists of cutting a length of wire, bending it to loop form to provide two substantially parallel conductor bars, one bar being so located as to occupy a position in the outer layer of the winding and the other a position in the inner layer of the winding, and striking the free ends of the bars to provide wedge shaped lugs having longitudinally extending grooves in their sides wherein a commutator binding means may extend, said lugs being suitably positioned and each of sufiicient axial length and radial width for a commutator segment, but the two said lugs taken together being required to provide suflicient thickness for the same said purpose.

4:. lhe method of making a winding unit for a bar wound armature which consists of providing bars having a cross section of substantially the width and half the depth of a winding aperture of the core of said armature, folding a bar back upon itself to hairpln form, spreading the two legs of the hairpin apart to provide axially parallel conductor portions conforming to circumferentially spaced apart apertures of said core, the one to the inner half of one said aperture and the other to the outer half of the other said aperture, further spreading the free ends to other axially parallel positions circumferentiah ly spaced apart from the conductor portions but equidistant from the armature axis, and striking said free ends in a die to bring them to a wedge shaped cross section suitable for divisions of the commutator.

In testimony whereof, I hereunto sign my name.

VINCENT G. APPLE. 

